PRIMER COMPOSITION

摘要

PROBLEM TO BE SOLVED: To obtain a primer composition which does not cause intercoat adhesion failure even when raining intervenes between primer coating and waterproofing and is improved in the water-resistant adhesiveness after the application of a waterproofing agent by incorporating two specified isocyanate-terminated prepolymers with an organic solvent. SOLUTION: This composition is prepared by dissolving in an organic solvent a mixture comprising (A) an isocyanate-terminated prepolymer obtained by reacting a bisphenol-skeleton-containing polyol of the formula with 4,4'- methylene-bis(phenyl isocyanate) in an charged isocyanate/hydroxyl equivalent ratio of 2.0-5.0 and (B) an isocyanate-terminated prepolymer obtained by reacting a bisphenol-skeleton-containing polyol of the formula with tolylene diisocyanate in an isocyanate/hydroxyl feed ratio of 1.6-2.1 by equivalent in a weight ratio of 10/0 to 2.5-7.5. In the formula, R1 and R2 are each H or a lower alkyl; D is a 2-4C alkylene; and (m) and (n) are each 1-10.